Extracardiac adult and fetal types rhabdomyomas probably originate from skeletal muscle of the third and fourth branchial arches.1, 7 Their neoplastic nature was not clear because tumor cells usually do not express cell proliferation markers such as Ki-67 and PCNA, resembling more likely hamartomas than neoplasms.7 This evidence concerns the gene MKI67 and rhabdomyoma.